In this study, the electrical and optical properties of a novel NiO-based homojunction p-i-n photodiode are reported. The p-i-n diode structure consists of Mg-doped, intrinsic and Cu-doped NiO from the top to the bottom layers, respectively. The photodiode structure was grown on a 0.7 % Nb-doped SrTiO3 (001) substrate using molecular beam epitaxy. The homojunction p-type NiO:Mg/i-NiO/n-type NiO:Cu exhibits diode characteristics. The ideality factor and barrier height of the diode are found to be 1.26 and 0.66 eV, respectively. The photoconductive properties of the photodiode were investigated by operating the diode under reverse bias, and spectral excitation of a Xe lamp. The responsivity of the photodiode is determined to be 295 mA/W at 3.9 eV. A constant photoresponse of the p-i-n photodiode between 3.75 eV and 6 eV with a responsivity of 250 mA/W is observed.
Bibliographical noteFunding Information:
This work was supported in part by the Scientific Research Projects Coordination Unit of Istanbul University ( FAB-2021-37290 and FBG-2021-37896 ). We thank Diamond Light Source for access and support in the use of the electron Physical Science Imaging Centre (Instrument E01 and proposal number MG30474–1) that contributed to the results presented here.
© 2022 Elsevier B.V.
- N-type NiO
- P-i-n junction
- P-type NiO
- Ultraviolet photodiode
- Wide bandgap